Performing photoreactions, such as photocuring or photochemistry, involves delivering actinic light (usually ultraviolet or visible light) from an actinic light source to a particular photoreactive material.
In many instances, the photoreactive material is arranged such that it can be exposed directly with the actinic light from an actinic light source, perhaps with the assistance of collimating or focusing optics. However, there are cases where the photoreactive material cannot be directly exposed in “free space” with the actinic light. For example, the photoreactive material may be between two pieces of metal that need to be bonding by photocuring the photoreactive material. The photoreactive material may be inside an opaque pipe or other type of enclosed or semi-enclosed container, or beneath an opaque layer of paint. While the photoreactive material may be arranged such that it presents a surface that may receive free-space illumination of actinic light, the arrangement may be such that the actinic light cannot reach throughout the photoreactive material. This results in only a portion of the photoreactive material being exposed and undergoing the particular photoreaction.
Thus, there is a need for performing photoreactions in a manner that allows for actinic light to be delivered to photoreactive materials, particularly in circumstances where free-space illumination of actinic radiation cannot be effectively used to create a photoreaction throughout the photoreactive material.